The vulnerability in the Linux kernel ALSA aloop driver involves a use-after-free condition triggered during a format-change stop. Specifically, loopback_check_format() may stop the capture side when playback starts with parameters that no longer match the capture stream. Although peer lookup was moved under cable->lock, snd_pcm_stop() runs after releasing the lock, allowing a concurrent close to clear the capture entry and free its runtime while playback still holds a stale pointer. The fix introduces a per-cable count of in-flight peer stops and delays freeing the cable until all stops complete, preventing use-after-free.

Successful exploitation could lead to memory corruption due to use-after-free, potentially causing system instability or allowing an attacker with local privileges to escalate privileges or cause denial of service. The CVSS vector indicates local attack vector with low complexity and no user interaction, with high impact on confidentiality, integrity, and availability.

A security update for the Linux kernel addressing this vulnerability has been released by vendors including Red Hat. Systems should apply the official kernel updates and reboot to activate the fix. Patch status is confirmed by vendor advisories. No additional mitigation is required beyond applying the official patch.